Magnetic separator



y 1950 5. 5. FRANTZ 2,508,666

msma'rxc SEPARATOR I Filed Dec. 12, 1939 INVENTOR. Samuel 6165 9011, Man 521 BY =amm9 gnaw.

ATTORNEYS.

Patented May 23,

'iJNlTED STATES PATENT OFFICE MAGNETIC SEPARATOR Samuel G. Frantz, Princeton, N. J.

Application December 12, 1939, Serial No. 308,850

11 Claims. 1

This invention relates to magnetic separators, and is an improvement upon the separator shown in my prior Patent No. 2,074,085, granted March 16, 1937.

My improvement consists in providing permanent magnets for magnetizing the attractors, so arranged with respect to each other and to the attractors which they magnetize, as to produce a high degree of magnetization in the attractors. In my machine, permanent magnets are placed in close proximity to the top and bottom ends of the stack of magnetized attractors and are magnetized axially and in the same direction. As a consequence, the attractors are highly magnetized and there is very little flux leakage.

My improvement also consists in providing permanent magnets 01' such design as to facilitate the flow of the material to be separated through the machine. In my machine each permanent magnet is provided with flow channels or passages and the material to be separated flows inwardly through the channels of the lower magnet to the cleaning chamber, thence through the stack of magnetized attractors in said chamber, and thence ouwardly through the channels of the upper magnet, being efllciently cleaned with ,very little pressure drop, due to friction, during such travel.

Other improvements and advantages will be apparent as the description proceeds.

In the accompanying drawings:

Fig. l is a vertical section through a preferred embodiment of my invention.

Fig. 2 is a plan view of the upper permanent magnet, removed.

Fig. 3 is a section on theline 3-3 of Fig. 2.

Fig.- 4 is a plan view of the lower permanent magnet, removed. 7

Fig. 5 is a section on the line 5-5 of Fig. 4, and

Fig. 6 is a plan view of one of the attractors or screens composing the attractor stack, removed.

My improved magnetic separator comprises a head ill of iron, steel or other magnetizable material having an inlet H for the intake of the material to be separated and an outlet I2 for discharging the cleaned material.

Preferably, although not necessarily. the inlet H and outlet l2 are located adjacent the upper end of the head ill at opposite sides thereof. Obviously, however, these openings may be otherwise located.

Depending from the underside of the head It is a closed bottom shell it of iron, steel or other magnetizable material. This shell is secured to 2 the head I0 in any desired manner. As shown, a rod I4 is threaded at its upper end into the head and extends axially oi the machine beyond the closed bottom of the shell l3, and is there provided with a. wing nut I! or its equivalent.

The assembly is made fluid-tight at this point by means of a gasket it about the rod H which is compressed against the bottom of the shell by means of a washer I! on said rod. At its upper end, the shell I3 is made fluid-tight with the head by means of a gasket l8.

Arranged concentrically about the rod N is an inner tube or casing 19 and an outer tube or casing 20 both of non-magnetic material. These tubes define with each other an annular cleaning chamber 2| within which is assembled a vertical stack of superposed horizontally placed attractors or screens 22 similar to those shown in my said patent aforesaid.

These attractors may be slightly separated ii desired by spacing rings 23 in order to avoid local short circuiting of magnetic flux which would occur at points of contact if spacers were not used, and also to provide more room at the magnetized edges of the screens for the accumulation and storage of magnetic material withdrawn from the flow stream.

The outer tube 20 defines with the enclosing shell IS an annular flow passage 24 connecting at its upper end with the intake opening II and at its lower end with the cleaning chamber 2i containing the attractors 22.

Mounted at the ends of the attractor stack are an upper and a lower permanent magnet 25 and 26, respectively. These magnets are -co-axial with the rod ll. The upper magnet 25 preferably rests upon the upper edge of the inner tube l9 and is enclosed by the upper end of the outer tube 20. The lower magnet 26 preferably'encloses the lower end of said inner tube It and supports the lower edge of said outer tube 20.

Both magnets are magnetized axially and in the same direction, either upwardly or downwardly. For the purposes of this application, it may be assumed that they are so magnetized as to cause the magnetic flux to travel downwardly through the attractors placed in the gap between said magnets.

The magnet circuit is as .follows:

Starting with the upper magnet, the flux travels downwardly through the attractors, then through the lower magnet, and outwardly and then upwardly through the shell iii to the head I! and back into the top of the upper magnet.

Because of the close proximity of the adjacent races of the magnets to the attractors, a high degree of magnetization is obtained in the attractors, with very little leakage flux. Consequently, most or the flux passing through the magnets also passes usefully through the attractors.

The separator illustrated is particularly adapted for the magnetic removal of iron and other magnetic particles from liquids.

In such action, the liquid enters the machine at H and flows downwardly between the shell l3 and outer tube 20. Reaching the lower end of said tube, it flows inwardly and upwardly through slots, passages or other channels 26' in the lower magnet into and through the cleaning chamber II containing the highly magnetized attractors which catch and hold any magnetic particles that may be in the liquid.

After passing through the uppermost attractor of the stack, the cleaned liquid emerges through slots, passages or other channels 25' in the upper magnet 25 and from the central opening at the top of this magnet discharges into a cavity Ill inthe head I communicating with the outlet ll. This flow action is generally indicated in Fig. 1 by the arrows.

The attractors, being of open construction, permit a flow of liquid through the chamber or gap separating the magnets and provide local concentrations of magnetic flux at their magnetized edges.

Various modifications in construction and arrangement may obviously be made within the spirit and scope of my invention as defined by the appended claims.

What I therefore claim and desire to secure by Letters Patent is:

1. A magnetic separator comprising a. body provided with inlet and outlet flow passages, two spaced co-axial permanent magnets magnetized axially and in the same direction, and a plurality of magnetizable attractors of open construction in the gap between said magnets, a casing surrounding said gap, a shell of magnetizable material surrounding said magnets and said casing and spaced therefrom to define a flow passage communicating with said inlet, said body, magnets, attractors, and shell forming a closed magnetic circuit, and means comprising channels in said magnets for conducting a flow of liquid from said flow passage to the gap between said magnets and from said gap to said outlet.

tubes and closing the upper and lower ends of permanent magnets spaced along an axis and each magnetized from face to race in the same direction substantially parallel to the axis, return circuit means comprising material of high magnetic permeability in substantial contact with the outer faces of the magnets, the inner faces of said magnets being opposed to and spaced from each other, a casing surrounding the gap between them, a plurality of magnetizable attractors of open construction within said gap. the magnetic flux through said magnets, gap, and attractors being substantially parallel to said axis, and flow means leading to the inner faces of said magnets for conducting a fluid stream into and out of said casing, the flow in said casing being substantially parallel to said axis and magnetic flux.

7. The separator of claim 6, said flow means comprising channels in said magnets.

8. A magnetic separator comprising a liquidtight casing of magnetizable material formed with 2. A magnetic separator comprising a head having an inlet for material to be cleaned and outlet for the cleaned material, a closed-bottom shell attached to the under face of said head, an

inner and an outer tube concentrically arranged within said shell in spaced relation to each other and to the shell, the space between the outer tube and the shell constituting a flow passage for material to be cleaned communicating with said inlet, and the space between said inner and outer tubes constituting a cleaning chamber communicating at one end with said flow passage and at its other end with said discharge, outlet, a stack of magnetizable attractors in said cleaning chamber, and a pair oi permanent magnets mounted in spaced co-axial relation to each other at the respective ends of said stack and each having a passage therethrough for placing the ends of said cleaning chamber in communication respectively with said flow passage and said discharge outlet.

3. The separator of claim 2, the magnets occupying the space between said inner and outer an inlet and an outlet, an annular permanent magnet within said casing, one pole of said magnet being in contact with an internal face of said casing, said casing providing a low reluctance path for the flux of said magnet and being so disposed as to leave an annular gap in the magnetic cir cult, means for supporting a plurality of removable magnetizable attractor elements in said gap, a duct within said casing leading from said inlet to one side of the said annular gap, and a second duct within said casing leading from the other side of said annular gap to said outlet, said ducts being arranged to convey liquid bearing magnetizable particles through said gap in contact with said attractor elements.

9. A magnetic separator comprising a liquidtight casing of magnetizable material formed with inlet and outlet passages adjacent one end thereof, an annular permanent magnet within said casing adjacent said end, one pole of said magnet being in contact with an internal face of said casing, said casing providing a low reluctance path for the flux of said magnet and being so disposed as to leave an annular gap in said magnetic circult, means for supporting a plurality of magnetizable attractor elements within said gap, a duct within said casing disposed axially through said annular magnet and communicating with one of said passages, and a second duct within said casing communicating with the other of said passages, said ducts leading, respectively, to opposite sides of said annular gap for conveying a liquid bearing magnetizable particles through said gap in contact with said attractor elements.

10. A magnetic separator comprising a liquidtight casing of magnetizable material formed with an inlet and an outlet, an annular permanent magnet within said casing, one pole of said magnet being in contact with an internal face of said casing, said casing providing a low reluctance path for the flux of said magnet and being so disposed as to leave an annular gap in the mag-- N am netie circuit, means for supporting a plurality of removable magnetizable attractor elements in said gap, a duct within said casing leading from said inlet to one side oi the said annular gap, and a second duct within said casing leading from the other side of said annular gap to said outlet, said ducts being arranged to convey a liquid bearing magnetizable particles through said gap in contact with said attractor elements, said casing being made in separable parts, one part having said inlet and outlet connections and another part comprising awall transverse to the axis of said annular magnet and removable from said firstmentioned part, said removable wall section bein of a diameter greater than said annular gap to permit the removal of said attractor elements without disturbing said inlet and outlet connections.

11. A magnetic separator comprising a casing of magnetizable material formed with an inlet and an outlet, an axially magnetized annular permanent magnet within said casing, one pole of said magnet being substantially in contact with an internal face of said casing, said casing providing a low reluctance path for the flux of said magnet gs REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,683,780 Hulsmeyer Sept. 11, 1928 2,074,085 Frantz Mar. 16, 193? 2,149,764 Frei Mar. '1, 1939 FOREIGN PATENTS Number Country Date 303,076 Great Britain Dec. 2'1, 1928 

